The hush-hush project is understood to be in early development, with work on the first of the four books under way, industry sources say. Weta Workshops is also believed to be working on designs for the science fiction series, which features giant mobile cities. A spokesman for Jackson did not deny the project was on the books yesterday, but said "any comment should come from Peter". Jackson, who is understood to have had the rights to the books for some time, was unavailable for comment.